You got it, but it is not what I prefer. All what I am talking about is gained by doing, over the long years and I try my hardest to suit the bees and not me. I live in a nice house, two of them actually and there should be the place where I can thinker and decorate to my hearts desire?.
Bees are the ones that live outside in boxes that we stuck them in to. If they would have a chance I am sure that they would find something diferent than what we put them in? By the same token, most of them would surely die over the winter.
Most hard core beeks call this 'Natures way of ensuring the survival of the fittest'. Which of course is correct but it is also all wrong.
Mother Nature has nothing to do if bees, for some reason or other, found a home in a rock crevice which is too small, or even in a flood plain, or area where spring thaw will drown them, or at best, make their home damp. Or they did not collect enough honey, polen, to last them through the winter. Or are in a tree where the bear will tear them apart?
Bees can not control such things - only we can help them there. So, when you people find a colony of bees that has found a home, where things might go wrong, it would be nice if you would help them, by cutting them out and saving the little fools.
Now, back to the question at hand.
I have bottom and top entrances. Would not keep bees without them. (I wish people would forget about centre hole? Some call it even a handhold?) This, bottom top thing, works well and if bottom friezes or gets buried in snow no harm can befall the bees. They always have the upper hole. Even if the whole hive is buried in snow, they will still survive, cause for bees enough oxygen gets through, or is released from snow for them to survive. They will move around in this cavity under the snow with no ill effect to them.
When I lived in Europe I was active in avalanche rescue, cause I had an German Shepard and we both helped when help was needed. People survived for long time under the snow as long as it was not packed too tightly around them.. If they were able to move and a bit enlarge such a hole, they said that breathing was not the problem.
I am not a scientist and have no answers to explain, to inquisitive minds in fancy words, why is so? All I strive for and care for - is to keep my bees alive and well.
Centre hole, feeding hole is not meant for ventilation, cause it draws, creates cross-draft through the cluster. I wrote about that already? But, if the hive was under the snow, than this is negligible and does no harm. It would be a diferent story if the hive was out in the open, or worse, when wind is howling! There are many a variables over which one can debate and even argue for ever.
If something works for me, I am satisfied and I have no further need to go and nitpick, tear everything down and give myself more questions than I know the answers to. All I know is, poking around and grasping hopelessly for straws, such doing will only give me some more gray hairs, perhaps a headache or two and nothing more.
I always cary in my mind some words from a "swamp person" from a Louisiana bayou, making a living catching gators. Some time ago, National Geographic had sent there a team of scientists and a film crew, to record what was going on. They were even concerned that too many a gator was being cut? (It's a tree-hugger thing) This man did not like the idea of city-slickers being there, much less - that he was forced by a processor that he takes those people into the swamps and show them what it takes to make a living catching gators on a fishing hook. Man did not like it, but said that he must go by their time honouring tradition, that one does not bite the hand that feeds him.
After much stalling, showing of and acting macho, by the visiting crew, the man turned to the most mouthy scientist and calmly told him this: "Mista, you just shut you mouth right now! You may be book smart, but you ain't no common sense smart! Here is a diferent ball game! Here a common sense means if you live, or you die! No book will save your sorry ass here."
Thanks for the answer Trot. So if I understand you correctly you prefer to ventilate from the bottom and not through the inner cover hole. Correct?